The birth of a book 3: Web printing

The printing principle of the rotary offset press is basically the same as that of the sheet offset offset press. However, because the printing speed of the rotary press is very high, the front and back are printed at the same time, and it is equipped with an automatic folding device, so the volume of an eight-color commercial rotary press is very large. Of course, its printing efficiency is also very high. According to rough statistics, the output of one rotary machine is equivalent to seven or eight sets of four-color offset printing presses.

The following are the characteristics of the rotary machine:

1. Commercial rotary printing machines use roll paper, which is suitable for thin paper with a paper thickness below 105g.

2. The printing speed of the rotary press is very high, with an average speed of 50,000 printed sheets per hour, while the printing speed of a general sheet-fed offset printing press is below 10,000. In addition, the rotary press is printing on both sides of the front and back, while the flat sheet machine is printing on one side, and after the ink is basically dry, the printing is reversed.

3. The wonderful thing about the rotary press is that the printed sheets are quickly dried and disconnected after printing, and the pages are folded out directly according to different binding methods.

4. The rotary machine is suitable for printed matter with large number of prints and short delivery time, such as magazines and discount books in supermarkets.

Rotary printing presses have different structures and different prices depending on the substrates. There are newspapers, stickers, and documents, etc., and our company's rotary machines are high-end commercial rotary machines (model Heidelberg M600-C24), which are printed in four colors at the same time. Specially printed high-end periodicals can also print color textbooks and newspaper color inserts.

Printing knowledge:

＊ How to overcome the printing pressure and increase the mechanical dots

In the printing process, the transfer of ink and the transfer of imprints require appropriate printing pressure. The extrusion of the cylinder and the deformation of the blanket will inevitably cause the deformation and increase of the dot. Therefore, when printing the PS version, it is necessary to combine different models (different printing machines have different dot increase values) to select the appropriate exposure time, so that the dots on the PS version are slightly smaller than the proof, the printed matter can be consistent with the sample .

When you stand in front of a large commercial rotating machine that moves at full speed, the huge roar and the colorful prints in front of you like a waterfall are really a feast for hearing and vision for someone who is engaged in or loves printing. What a heart-warming symphony!